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A method of estimating the load carrying capacity of steel W-shape beams with reinforced eccentric web openings is developed. The analysis is limited to single rectangular openings and to reinforcing bars positioned above and below the opening and oriented parallel to the edges of the opening. Computer solutions in the form of interaction diagrams relating the shear and moment at the center of the opening can be generated using an iterative process. The coordinates of points defining an approximate interaction diagram suitable for design are also derived. Examples of interaction diagrams for a specified yield stress and selected beam and opening dimensions are presented to illustrate the effects of varying reinforcing area, opening length, and opening eccentricity on the strength of a beam with a web opening. For the range of opening eccentricity considered in the examples, the eccentricity could be neglected for design purposes.

A discrete version of the maximum principle is applied to a multi-copy traffic assignment problem. This technique allows the use of nonlinear travel time-traffic volume relationships which are considered to be more realistic than the constant travel time relationship now generally used. The technique is demonstrated through the use of a prototype urban street and freeway network. The technique produces realistic results that achieve near minimal overall travel time on the network.

A plate, containing a sizeable rectangular opening with circular corner fillets, subjected to uniaxial tension, is analyzed by a finite element method. Values are obtained for the maximum stress in an unreinforced plate, a plate with a ring of reinforcing around the edge of the opening, and for several cases with strips of reinforcing parallel to the direction of the applied load. These values are used as a measure of the effectiveness of the various reinforcing configurations studied. Experimental confirmation of the magnitude of the maximum stress is presented for the unreinforced plate and for one reinforced case. The results presented give some insight into the relative effectiveness of the different reinforcing configurations in reducing the maximum stresses occurring in the plate.

One of least known methods of garbage and refuse disposal, composting, is currently being considered as important means of conserving natural resources as well as of disposing of solid wastes; factors affecting high rate composting. (36 refs.)

This work deals with the problem of traffic assignment with a nonlinear travel-time function. The nonlinear travel-time function makes it possible to simulate congestion on urban streets in a more realistic manner. The optimal traffic assignment pattern is obtained by using a variational technique for a multicopy network problem with nonlinear travel-time functions and turn penalties.

The use of tapered sheet stock is generating an increased demand for the design characteristics of tapered plates. The purpose of this study was to quantify the effects of various taper ratios on the first five natural frequencies of vibration for a series of cantilevered right triangular tapered plates.

Sixteen elastic tests and three ultimate load tests on A36 steel W 12x45 beams with reinforced rectangular openings in the web at middepth are described and analyzed. The experimental variables were the moment-shear ratio at the opening and the details of the horizontal reinforcing bars which were used above and below the openings. It is concluded that fillet welds placed on only one side of the reinforcing bars provided an adequate connection to the web, both for one and two-sided reinforcing bars, and that the use of reinforcing bars on only one side of the web had no interpretable effect on the strength and behavior of the beams. It is also concluded that designing the extension of the reinforcing bars beyond the edges of the opening to develop the strength of the bars in the welds is a reasonable and satisfactory approach to this detail.

Empirical analysis of the primary structures of 10 mammalian C-peptides has indicated a conservation of conformation. The positioning of the C-peptide in the proinsulin molecule is essentially defined by the proposed secondary structure, the covalent connection to the A1 and B30 residues of insulin and the requirement that C-peptide lies against the exposed surface of the insulin hexamer, allowing a three-dimensional structure for proinsulin to be predicted. Conserved residues in the C-peptide are proximate to residues in insulin that are also conserved, suggesting that interactions between these residues are highly probable. Residues in insulin thought to be important for biological activity are principally those that interact with the C-peptide residues. The role of the C-peptide region in proinsulin in preventing expression of insulin activity and for nucleation of the folding of the prohormone are discussed.

Four protected oligopeptolides of L-leucine and L-2-hydroxy-4-methylpentanoic acid, with benzyloxycarbonyl as N-protecting and t-butyl as C-protecting group, have been synthesised; the depside linkage was formed by the action of dicyclohexylcarbodi-imide in ethereal pyridine. The action of triethylamine on the chloride hydrochlorides of the deprotected oligopeptolides gave the macromolecular sequential polypeptolides (I; x= 1, 2, or 3) in 40–45% yield with molecular weights, Mn, of 24,000, 32,000, and 46,000, respectively. An improved method of preparation of L-2-acetoxy-4-methylpentanoic acid from L-leucine is described.

Conformational aspects of a series of copolymers of L-Leucine and L-leucine [poly-(LysxLeuy)] containing 0 to 0.41 mole fraction L-leucine have been studied by circular dichroism (CD) and potentiometric titration in 0.05M KF solution. CD studies on the α-helical conformation showed a dependence of the magnitude of the CD ellipticity band at 222 nm on copolymer composition; the [θ]222 decreasing with higher leucine contents. This was interpreted as the result of an increase of the hydrophobicity of the environment of the amide group due to the presence of the leucyl residues. Values of the Zimm-Rice parameter, σ, for the copolymers were obtained from the potentiometric titrations and used to fit theoretical curves to the experimental data. Using the variation of σ with polymer composition, a value of σ for the leucyl residue was estimated to be 6.3 × 10−2, assuming independence of σ on the amino acid sequence in the copolymer. The free energy change for the conversion of one mole residue from uncharged helix to uncharged coil, ΔGhc°, was also obtained from the titration data for each copolymer up to a leucine mole fraction of 0.16; a value of 385 cal mole−1 was estimated for ΔGhc° for a leucyl residue. These values for σ and ΔGhc° are compared with other values in the literature for various amino acid residues obtained from titration and melting curve data.